Pump

ABSTRACT

A rotary centrifugal pump having an axial inlet and discharge in a casing together with an impeller having liquid impelling vanes on both surfaces thereof with the impeller having central openings enabling inlet liquid to be impelled by vanes on both surfaces of the impeller. The pump includes a pressured water cooled bearing and a seal in which grease or other lubricant is maintained under pressure by the liquid being pumped. The pump is adapted for use as a single stage or multiple stage and is capable of producing relatively high pressures and high volume discharge.

United States Patent [191 Ogles [4 June 11, 1974 PUMP [75] Inventor:Ethridge F. Ogles, Ada, Okla.

[73] Assignee: Selgo Pumps, lnc., Ada, Okla.

[22] Filed: Oct. 19, 1972 [21] Appl. No.: 298,823

[52] US. Cl 415/111, 415/55, 415/180, 415/212 [51] Int. Cl. F0ld 11/00[58] Field of Search 415/52, 55, 59, 111, 180, 415/182, 212

[56] References Cited UNITED STATES PATENTS 2,207,183 7/1940 Thrush4l5/l82 2,276,965 3/1942 Halliday 4l5/l ll 2,406,947 9/1946 Harlamoff4l5/l l 1 2,427,656 9/1947 Blom 4l5/l ll 5/1956 Garraway.... 8/1971415/52 Ogleby 415/111 Primary ExaminerC. J. Husar Attorney, Agent, orFirm-Clarence A. OBrien; Harvey B. Jacobson [5 7 ABSTRACT A rotarycentrifugal pump having an axial inlet and discharge in a casingtogether with an impeller having liquid impelling vanes on both surfacesthereof with the impeller having central openings enabling inlet liquidto be impelled by vanes on both surfaces of the impeller. The pumpincludes a pressured water cooled bearing and a seal in which grease orother lubricant is maintained under pressure by the liquid being pumped.The pump is adapted for use .as a single stage or multiple stage and iscapable of producing relatively high pressures and high volumedischarge,

13 Claims, 7 Drawing Figures PATENTEDJUM 1 1 mm 3.8 l 6; 020

sum 1 or 4 PATENTEDJux 1 I ma SHEEI 2 (IF 4 NSQ PATENTEDJUKI 1 m4 sawan; 4

mtmium 11 m 3.8 1 SL020 SHEET &0? 4

PUMP

BACKGROUND OF THE INVENTION 1. Field of the Invention The presentinvention generally relates to a rotary pump having axial intake anddischarge and an impeller having vanes on both sides thereof forproducing a high discharge pressure and a novel and unique bearing andsealing arrangement for the drive shaft in relation to the intake of thepump.

2. Description of the Prior Art Rotary pumps generally of thecentrifugal type have been provided for pumping liquids under variouscircumstances. An example of one type pump for this purpose is found inmy prior US. Pat. No. 3,363,576, issued .Ian. 16, 1968. Knowncentrifugal pumps have been performed satisfactorily under someconditions but in some situations, such pumps either performinefficiently or inadequately.

SUMMARY OF THE INVENTION An object of the present invention is toprovide a rotary pump incorporating a casing having a rotary impellerdisposed therein with the impeller having vanes on both surfaces thereofand a central opening to enable fluid to be pumped from a single axialinlet by both surfaces of the impeller.

Another object of the invention is to provide a pump in which the casingis provided with passageways for guiding, directing and discharging thefluid being pumped from the outer peripheral portion of the impeller ina radially inward direction for discharge axially of the pump or axiallyinto a subsequent stage of the pump.

Another object of the invention is to provide a pump in accordance withthe preceding objects in which the power shaft which drives the impelleris supported from the casing or other stationary support by a bearingassembly lubricated by the fluid being pumped and the power shaft isalso sealed by a lubricated seal arrangement in which the lubricant ismaintained under pressure by the pressure of the fluid being pumped.

A further important object of the present invention is to provide arotary pump in which the impeller has central annular ring membersthereon generally in sealing relation to the housing with the impellerbeing accurately positioned and supported in relation to the casing bythe bearing and supporting structure for the drive shaft and a tailshaft provided on the impeller that is journalled in the casing.

Yet another significant object of the invention is to provide a rotarypump of thecentrifugal type capable of discharge of liquid at arelatively high volume and high pressure which is efficient in operationcapable of assembly into a single stage or any number of stagesdepending upon the output pressure desired, long lasting and dependablein operation and relatively inexpensive to manufacture and maintain.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view ofthe pump.

FIG. 2 is a longitudinal, sectional view taken substantially upon aplane passing along section line 2-2 of FIG. 1 illustrating therelationship of the structural components of the pump.

FIG. 3 is an end elevational view of the impeller and associateddeflector ring and casing with the intake portion of the casing removed.

FIG. 4 is a view similar to FIG. 3 but with the impeller and deflectorring removed.

FIG. 5 is an exploded group perspective view illustrating the componentsof the pump and their relationship.

FIG. 6 is an elevational view, partially in section, illustrating theadapter insert by which the pump may be converted from a single stage toa multiple stage.

FIG. 7 is a group perspective view of the extension assembly used in themultiple stage pump.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now specifically tothe drawings, the pump of the present invention is generally designatedby reference numeral 10 and includes a casing generally designated bythe numeral 12 which includes an intake portion 14 and a dischargeportion 16. The pump is supplied with rotational power by virtue of apower shaft 18 oriented longitudinally in the casing 12 with the inputend thereof projecting from the intake portion of the casing forconnection with a suitable power source such as an internal combustionengine, electric motor or the like by any suitable means so that shaft18 may be rotated at a desired rotational speed with a desired torque.

The intake portion 14 of the casing 12 includes a longitudinallyextending hollow cylindrical member 20 having a circular plate 22 rigidwith one end thereof with reinforcing gussets 24 bracing and rigidifyingthe tubular member 20 and plate 22 with respect to each other. Thetubular member 20 is provided with an angularly extending adapter tube26 which terminates in a laterally extending tubular element 28 thatforms an inlet for the pump and is connected to a suitable pipe, conduitor the like for supplying liquid such as water to the pump.

The gussets 24 extend beyond the end of the tubular member 20 andrigidly support an annular flange 30 having a plurality of apertures 32therein on which is mounted a bearing assembly 34 which journals andsupports the shaft 18. The end of the tubular member 20 is spaced fromthe flange 30 and receives a seal assembly 36 which sealingly engagesthe shaft 18 and prevents water leakage along the shaft 18 from theinterior of the pump.

The casing 12 includes a hollow chamber 38 which may be considered theworking chamber of the pump and is annular in configuration and thischamber receives an impeller generally designated by the numeral 40 andan annular deflector ring 42 which is stationary with respect to thecasing with the impeller rotating with the shaft 18.

As illustrated in FIG. 2, the plate 22 abuts and is rigid with a flange44 on the discharge portion 16 of the casing with the periphery of theplate 22 also defining a flange that is secured in rigid relation withthe flange 44 by suitable through bolts received in apertures 46. Theinterior surface of the plage 22 is inclined as at 48 with the inneredge of the inclined surface 48 merging with the interior of the tubularmember 28 and the outer edge of the inclined surface 48 being defined bya shoulder 50 that extends peripherally of the plate 22 inwardly of thecircumference thereof.

The discharge portion of the casing 16 also includes a plate 52 whichhas an inclined surface 54 that is integral with the flange 44 anddiverges from the inclined surface 48 and cooperates therewith to definethe hollow chamber 38 which receives the impeller 40. Centrally of theplate 52, there is provided an annular shoulder or recess 56 that is thesame diameter as and in alignment with the interior of the tubularmember with the rear limit of the recess or shoulder 56 being defined bya circular plate 58 which forms a rearward partition wall or closure forthe hollow chamber 38.

As illustrated in FIG. 5, the impeller 40 includes a circular plate 60having a centrally disposed tubular hub 62 therein which extends to bothsides of the plate 60.

Each side of the plate 60 is provided with a plurality of radiallyextending but arcuately curved vanes 64 and 66 with the vanes 64 and 66being in alternate relationship. The vanes 64 extend completely inwardlyto and are joined with the hub 62 while the inner ends of the vanes 66terminate in circumferentially spaced relation to the hub 62. The innerends of the vanes 64 have the same depth as the length of the hub 62projecting from the plate 60 with the inner ends of the vanes 64 beingdesignatedvby numeral 68 with the outer ends of the inner end portions68 of the vanes 64 defining axially extending shoulders on which ismounted an annular ring 70 that is rigidly secured to the shouldersdefined by the juncture of the outer portion of the vane 64 and theinner portion 68 thereof with the outer edge of the ring 70 generallybeing flush with the end of the hub 62 as illustrated in FIG. 2. Thevanes terminate in alignment with the ring 70 with the vanes 64 and 66being rigidly secured to the plate 60 and substantially equally spacedwith the omission of the inner ends of the vanes 66 providing an openarea inwardly of the ring with an elongated and generally oval-shapedopening 72 being provided in the plate 60 with the openings 72communicating between the two sides of the plate 60. The relationship ofthe openings 72, the vanes 64 and 66 and the annular ring 70 isillustrated in F IG. 3 with the relationship of the rings 70 to theinterior of the tubular member 20 and the shoulder or recess 56 beingillustrated in FIG. 2. Thus, as water enters through the inlet 28 intothe tubular member 20 it will flow through the ring 70 received in thetubular member 20 with the water being divided with a portion of itbeing impelled outwardly along the surface of the impeller plate 60facing the tubular member 20 and the remaining portion of the waterpassing through the openings 72 and moving radially outwardly and beingimpelled by the vanes on the opposite side of the impeller plate 60thereby providing effective movement of the water or other liquid duringrotation of the impleller 40 in a clockwise direction as viewed in FIG.5 with the vanes being arcuately curved so that such rotation will impelThe deflector ring 42 includes an annular member 74 which has an inneredge 76 that closely surrounds the impeller plate 60 and has a widthsubstantially equal to the width of the combined impeller plate 60 andthe other ends of the vanes 64 and 66. The inner edge 76 of the annularmember 74 is provided with a plurality of arcuately extending notches 78defined by an outer periphery that tapers from the inner edge 76 towardsthe outer edge of the annular member in the direction of rotation of theimpeller plate 60 with the terminal edge of each notch 78 beingsubstantially radially disposed on the side of the annular member 74which faces the plate 22 as designated by numeral 80 in FIG. 5. Theopposite side of each notch 78, that is, where the notch communicateswith the surface of the annular member 74 which faces the dischargeportion 16 of the casing, the annular member is provided with anelongated arcuately curved and tapering groove 82 which extends in thedirection of rotation of the impeller so that water which is dischargedfrom the impeller will enter the notches 78 and be deflected or directedtoward the discharge portion 16 of the casing by the taperingconfiguration of the groove 82 which commences at the radial edge 80which is substantially a feather edge or very thin edge and inclinestowards the surface of the annular member 74 which faces the dischargeportion 16 of the casing. In order to seal the annular member 74 inrelation to the casing, an 0,-ring of neoprene, or the like designatedby numeral 84 is provided between the inner edge of the flange 44 whichhas a recess therein and a corresponding peripheral notch or recess inthe annular member 74. As illustrated, the plate 52 of the dischargeportion is closely adjacent to the annular member 74 and serves todefine the outer portion of the hollow chamber 38.

At the inner edge of the flange 44, a plurality of tapering channels orpassageways 86 are provided which commence as shallow grooves at theinlet end 88 thereof and progressively deepen in the direction ofrotation of the impeller and movement of the water or liquid until theyreach a maximum axial depth and communicate with a radially, inwardlyextending curved passageway 90 which extends to and communicates withthe interior of a tubular member 92 which forms an extension on theplate 58 and which includes an internally threaded extension 94 thatdefines a discharge pipe for the liquid being pumped. As illustrated inFIG. 4, three circumferentially spaced and isolated channels orpassageways 86 are provided with the tapering of the groove 86 beinggradual and continuous into the passageway 90 with the juncture betweenthe passageway 86 and the passageway 90 being smoothly curved androunded with the bottom limits of the passageway 86 also being curvedand generally of U-shaped configuration as illustrated in FIG. 2. Wherethe water or liquid exits from the passageway 90 into the hollowinterior of the tubular member 92, curved deflectors 96 are provided fordeflecting the water and making more efficient movement of the waterpossible.

The circular plate 58 is provided with a tubular member I00 extendingaxially in concentric relation to the tubular member 92 with the outerend thereof being rounded and closed as at 102. The tubular member 100forms a bearing member for an internally threaded extension 104 on theshaft 18. The extension 104 has an external surface that is journalledin the interior surface of the tubular member 100 and includes radialopenings 106 for receiving a spanner wrench or the like for threadingthe extension 104 rigidly onto the threaded end 108 of a reduced endportion 110 on the shaft 18. The reduced end portion 119 is receivedwithin the hub 62 of the impeller and includes a shoulder 112 at theinner end of the reduced end portion 110. The reduced end portionreceives a pair of tapered split collars 114 thereon with the innercollar having its large end abutted against the shoulder 112 and theouter collar received in the discharge end of the impeller hub 62 withthe end portions of the hub 62 being bevelled at an angle correspondingto the external surfaces of the collars 114. Also, the hub 62 and thereduced end portion 110 is grooved to receive a key 116 in order tosecurely lock the impeller 40 to the shaft 18 but enable disassemblythereof. A split collar 118 is disposed on the threaded portion 108 orthe outer end of the reduced end portion 110 with its large end abuttingthe large end of the rearmost collar 114 and the tapering surfacethereof is engaged with an internal tapering surface 120 on theextension 104 so that as the extension 104 is rotated, the internalthreads thereon will fixedly assemble the impeller 40 on the shaft 18with the shaft and impeller being concentrically oriented due to thetapered split collars 114 and 118. The threaded connection of theextension also enables the pump to be assembled into a multiple stagepump in a manner defined hereinafter and if desired, the tubular member100 may be provided with an inserted bushing or the like to extend thewear capabilities thereof.

Referring now specifically to FIG. 2, the bearing assembly 34 includes atubular sleeve 122 received on the power shaft between threaded portions124 and 126 thereon. The ends of the sleeve 122 are internally taperedat 128 and tapered split collars 130 are mounted on the shaft 18 inengagement with the tapered ends 128 on the sleeve 122 and nuts 132 arethreaded onto the threaded portions 124 and 126 to rigidly fix thesleeve 122 on the shaft 118 in concentric relation thereto. The externalsurface of the sleeve 122 is provided with reduced end portions 134 and136 which define shoulders 138 and 140 respectively. The reduced endportions 134 and 136 receive conventional bearing assemblies 142 and 144respectively with the inner races of the bearing assemblies engaging theshoulders 138 and 140 as illustrated in FIG. 2.

The bearing assembly 34 also includes an inner end plate 146 that isapertured for alignment with and engagement with the flange 30 and theapertures 32 therein with the apertures in theplate 146 being designatedby numeral 148. One side of the plate 146 is provided with a projectingshoulder 150 which extends into the interior of the flange 30 asillustrated in FIG. 2 and the opposite side of the plate 146 is providedwith a cylindrical extension 152 which defines a seat for engaging theexternal race of the bearing assembly 142. The bearing assembly 34 alsoincludes a tubular member 154 which includes an outwardly extendingflange 156 on its inner end having apertures 158 therein for engagementwith the plate 146 and registry with the openings therein so that boltsmay be employed for securing the bearing assembly to the flange 30. Theflange 156 and the internal dimension of the tubular member 154 engagethe extension 152 on the plate 146 to provide for accurate alignmentthereof and the outer end of the tubular member 154 is provided with aninwardly extending flange 160 which engages the outer race of thebearing assembly 144 and the bolts which extend through the flange 156and 30 and the plate 146 serve to retain the bearing assembly 34 inposition and accurately support and align the shaft 18 with respect tothe casing 12 which provides for accurate positioning of the rotaryimpeller in relation to the casing 12.

Disposed around the tubular member 154 is a water jacket 162 in the formof a tubular member having intumed flanges at each end thereof andO-ring seals 164 in the inner edge of the flanges in sealing engagementwith the tubular member 154. Threaded fittings 166 and 168 are providedin the water jacket 162 for receiving and connection with a water line170 communicated with the high pressure side of the pump such as thedischarge portion thereof and a similar pipe or conduit 172interconnects the fitting 168 and a similar fitting 174 on the inlet 28of the pump for providing for circulation of water and cooling of thebearing assembly 34.

Supporting brackets 176 and 178 are provided each of which includes asplit clamp sleeve 180 which encircles a reduced end portion 182 on thetubular member 154 and a corresponding surface on the discharge pipe ortubular member 92 respectively. This bracket will effectively retain thewater jacket 162 in position or any other suitable fastening means maybe provided for this purpose. The high pressure water pipe, tube or thelike 170 is communicated with the discharge portion 16 of the casing 12in any suitable manner such as by the use of a T-connection 184 providedwith a suitable pressure gauge 186 and the pipe or hose 170 is providedwith another similar T-connection 188 to which a branch pipe 190 isconnected that is associated with the seal assembly 36 with the pipe 190including a pressure regulator 192 and a check valve 194 disposedoutwardly of a cylinder 196 which has a piston movable therein and whichforces lubricant into the seal assembly with the lubricant being anysuitable grease or the like so that as pressure is exerted on theoutside of the piston within the cylinder 196, grease will be forcedinto the seal. A suitable check valve 198 is provided to prevent waterpressure in the pump from reverse flowing into the lubricant cylinderwhen the pump is not operating.

The seal assembly 36 includes a tubular member 200 receivingconventional seal elements with a retaining flange .204 serving toretain the seal members 202 within the tubular member 200. A passageway206 is provided in communication with the lubricant cylinder 196 throughthe check valve 198 for retaining lubricant under pressure within theseal. The inner end of the tubular member 200 is bevelled or tapered at208 and a collar 210 having a correspondingly tapered surface can engagethe end of the tubular member 200 and is longitudinally movable on theshaft 18 with an O-ring seal 212 being provided to prevent waterpressure in the pump from damping the seals 202 when the pump isinoperative inasmuch as the collar 210 serves as a protecting deviceagainst high pressure water coming into direct contact with the seals202. A limit collar 214 is secured to the shaft by a suitable setscrewin a manner to limit the longitudinal movement of the protective collar210 in relation to the tubular member 200. The inner end of the collar210 is bevelled or tapered and is maintained as small as possible inlength and diameter to eliminate unnecessary restrictions in the flowpath of the water passing into the pump.

With this construction, as the shaft is rotated, water enters throughthe inlet through the intake tubular member and is pumped by theimpeller and discharged through the notches and grooves in the deflectorring, the passageways in the discharge portion of the housing and outthrough tubular member 92 into the discharge pipe 94. All components aremaintained at a desired thickness which will provide the requisitestrength and at the same time all flow restrictions are reduced byeliminating sharp corners and providing deflecting vanes, guides and thelike for water passing through the pump.

The pump may be converted from a single stage pump as illustrated inFIG. 2 to a multiple stage pump as illustrated in FIG. 6 by theinsertion of an adapter 220 between the intake portion 14 of the casingand the discharge portion 16 thereof. The adapter 220 includes aduplicate of the plate 52, inclined surface 54 and the other associatedstructure of the discharge portion except that the tubular member isprovided at its rearmost end with a duplicate of the plate 22 and theinclined surface 48 thereon which, when combined with the dischargeportion 16 defines a second chamber the same as the hollow chamber 38 sothat a second rotor positioned thereon will pump the water through thesecond stage of the pump. In inserting the adapter, it is only necessaryto remove the discharge portion 16 from the intake portion 14 and theimpeller 40 which is assembled therewith. The extension 104 is alsoremoved and in lieu thereof, an extension adapter 222 is attached to thethreaded end 108 of the shaft 18. The

adapter 222 (see FIG. 7) is the same as the extension 104 except that itis provided with a rigid shaft portion 224 that has a threaded endportion 226 thus, in effect, forming an extensionof the reduced endportion 110 of the shaft 18 so that the extension 104 may be reappliedto the threaded end 226 in the same manner as it was originally appliedto the threaded end 108 with the association of all the other componentsremaining the same.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and'operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention.

What is claimed as new is as follows:

1. A rotary pump comprising a casing having an interior hollow chamber,a rotary impeller disposed in said chamber, a shaft connected with saidimpeller and extending exteriorly of the casing for rotatably drivingthe impeller, inlet means in said casing for admitting flowable materialto be pumped to the central portion of the impeller, said impellerincluding vanes thereon for impelling the material as the impellerrotates, outlet means incorporated into the casing and communicatingwith the portion of the casing receiving the periphery of the impellerfor receiving the material impelled by the impeller, said outlet meansincluding radially and inwardly extending passage defining meanscommunicating with an outlet pipe extending axially and generallycoincident to the rotational axis of the impeller.

2. The structure as defined in claim 1 wherein said impeller is in theform of a substantially circular plate, and vanes being disposedradially on each surface of the plate, the central portion of the plateincluding aperture means therein enabling flowable material to beimpelled by the vanes on both sides of the impeller.

3. The structure as defined in claim 1 wherein said rotary impellerincludes a hub received on said shaft, means rigidly fixing the hub tosaid shaft, each end of the hub having a tapering internal surface, apair of split tapered collets interposed between the shaft and thetapered ends of the hub with at least one of the collets beinglongitudinally movable on the shaft for centering the hub and impellerin relation to the shaft, and screw threaded means connected with theshaft for balancing the collits toward each other for securing the hubfixedly in concentric relation to the shaft.

4. The structure defined in claim 2 wherein said aperture means in theimpeller includes a plurality of openings through the plate to providehydraulic balance to both surfaces of the impeller plate.

g 5. A rotary pump comprising a casing having an interior hollowchamber, a rotary impeller disposed in said chamber, a shaft connectedwith said impeller and extending exteriorly of the casing for rotatablydriving the impeller, inlet means in said casing for admitting flowablematerial to be pumped to the central portion of the impeller, saidimpeller including vanes thereon for impelling the material as theimpeller rotates, outlet means incorporated into the casing andcommunicating with the portion of the casing receiving the periphery ofthe impeller for receiving the material impelled by the impeller, saidoutlet means including inwardly extending passage defining meanscommunicating with an outlet pipe generally coincident to the rotationalaxis of the impeller, said impeller being in the form of a substantiallycircular plate, said vanes being disposed radially on each surface ofthe plate, the central portion of the plate including aperture formingmeans therein enabling flowable material to be impelled by the vanes onboth sides of the impeller, said inlet means being in the form of atubular member having an inlet pipe communicated therewith, said shaftbeing disposed in said tubular member, seal means interconnecting theshaft and tubular member outwardly of the inlet pipe for sealing theshaft, and bearing means on said casing axially outwardly of the tubularmember for supporting said shaft in relation to the casing, and meansenabling circulation of cooling fluid in relation to the bearing meansfor preventing excessive temperatures occurring in the bearing means.

6. The structure as defined in claim 5 wherein said means enablingcirculation of cooling fluid including a pipe extending from theperiphery of the chamber in the casing for inlet of cooling fluid, apipe communicating with the tubular member to return the cooling fluidto the inlet means on the pump, and a jacket encircling the bearingmeans for enabling circulation of cooling fluid.

7. The structure as defined in claim 6 wherein said seal means includesa tubular member disposed concentrically within the tubular memberdefining the inlet means and receiving a plurality of seal rings thereinin sealing engagement with the shaft, lubrication means for said sealrings, said lubrication means including a piston and cylinder to forcelubrication means into the seal rings, and conduit meansinterconnectingthe lubrication cylinder and piston and the pipeextending from the periphery of the chamber in the casing for inlet ofcooling fluid to the jacket thereby providing pressure lubrication ofthe seal rings.

8. A rotary pump comprising a casing having an interior hollow chamber,a rotary imp'eller disposed in said chamber, a shaft connected with saidimpeller and extending exteriorly of the casing for rotary driving theimpeller, inlet means in said casing for admitting flowable material tobe pumped to the central portion of the impeller, said impellerincluding vanes thereon for impelling the material as the impellerrotates, outlet means incorporated into the casing and communicatingwith the portion of the casing receiving the periphery of the impellerfor receiving the material impelled by the impeller, sad outlet meansincluding inwardly extending passage defining means communicating withan outlet pipe generally coincident to the rotational axis of theimpeller, said impeller being in the form of a substantially circularplate, said vanes being disposed radially on each surface of the plate,the central portion of the plate including aperture forming meanstherein enabling flowable material to be impelled by the vanes on bothsides of the impeller, said impeller including a centrally disposedannular ring on each side thereof in encircling relation to the aperturemeans, one of the rings being received closely within the inlet means,said casing including a recess receiving the other annular ring 9. Arotary pump comprising a casing having an interior hollow chamber, arotary impeller disposed in said chamber, a shaft connected with saidimpeller and extending exteriorly of the casing for rotatably drivingthe impeller, inlet means in said casing for admitting flowable materialto be pumped to the central portion of the impeller, said impellerincluding vanes thereon for impelling the material as the impellerrotates, outlet means incorporated into the casing and communicatingwith the portion of the casing receiving the periphery of the impellerfor receiving the material impelled by the impeller, said outlet meansincluding inwardly extending passage defining means communicating withan outlet pipe generally coincident to the rotational axis of theimpeller, said outlet means including a substantially circular platedefining the rear surface of the chamber, said radially extendingpassage defining means being rigid with said plate, tapering inletchannels communicating the outer periphery of the chamber with theradial passage defining means.

10. The structure as defined in claim 9 wherein said casing is providedwith a deflector ring at the outer periphery of the impeller, saiddeflector ring including a plurality of radial notches therein with eachof the notches including an inclined surface extending circumferentiallyin the direction of rotation and inclined axially toward the channelsfor deflecting the material being pumped into the channels and passagedefining means for discharge.

11. The structure as defined in claim 10 together with an insert adapterfor converting the pump to a multiple stage pump, said casing includingan inlet portion and a discharge portion, said portions of the casingbeing separable at the outer periphery of the chamber, said insertadapter including a duplication of the discharge portion and the inletportion of the casing, a duplication of the impeller and deflector ringand an extension for the drive shaft for enabling a single or multiplenumber of insert adapters to be incorporated into the pump to enable anynumber of stages to be provided.

12. The structure defined in claim 11 wherein said extension for thedrive shaft is threadly connected thereto and includes a duplicateconnection with the impeller.

13. A rotary pump comprising a casing having a hollow interior chamberwith an inlet at one side thereof, a rotary impeller disposed withinsaid chamber and separating the chamber into two compartments with theinlet communicating with one compartment, said impeller including aplate of generally circular configuration with the periphery of the patebeing disposed closely adjacent the internal periphery of the chamber,said plate including centrally disposed aperture means communicating thecompartments of the chamber with each other and enabling inlet offlowable material from the inlet to both compartments for hydraulicallybalancing the impeller, said impeller plate including projecting vaneson both surfaces thereof for impelling flowable material thereof duringrotation, and discharge means communicated with the casing for dischargeof flowable material being pumped.

1. A rotary pump comprising a casing haVing an interior hollow chamber,a rotary impeller disposed in said chamber, a shaft connected with saidimpeller and extending exteriorly of the casing for rotatably drivingthe impeller, inlet means in said casing for admitting flowable materialto be pumped to the central portion of the impeller, said impellerincluding vanes thereon for impelling the material as the impellerrotates, outlet means incorporated into the casing and communicatingwith the portion of the casing receiving the periphery of the impellerfor receiving the material impelled by the impeller, said outlet meansincluding radially and inwardly extending passage defining meanscommunicating with an outlet pipe extending axially and generallycoincident to the rotational axis of the impeller.
 2. The structure asdefined in claim 1 wherein said impeller is in the form of asubstantially circular plate, and vanes being disposed radially on eachsurface of the plate, the central portion of the plate includingaperture means therein enabling flowable material to be impelled by thevanes on both sides of the impeller.
 3. The structure as defined inclaim 1 wherein said rotary impeller includes a hub received on saidshaft, means rigidly fixing the hub to said shaft, each end of the hubhaving a tapering internal surface, a pair of split tapered colletsinterposed between the shaft and the tapered ends of the hub with atleast one of the collets being longitudinally movable on the shaft forcentering the hub and impeller in relation to the shaft, and screwthreaded means connected with the shaft for balancing the collits towardeach other for securing the hub fixedly in concentric relation to theshaft.
 4. The structure defined in claim 2 wherein said aperture meansin the impeller includes a plurality of openings through the plate toprovide hydraulic balance to both surfaces of the impeller plate.
 5. Arotary pump comprising a casing having an interior hollow chamber, arotary impeller disposed in said chamber, a shaft connected with saidimpeller and extending exteriorly of the casing for rotatably drivingthe impeller, inlet means in said casing for admitting flowable materialto be pumped to the central portion of the impeller, said impellerincluding vanes thereon for impelling the material as the impellerrotates, outlet means incorporated into the casing and communicatingwith the portion of the casing receiving the periphery of the impellerfor receiving the material impelled by the impeller, said outlet meansincluding inwardly extending passage defining means communicating withan outlet pipe generally coincident to the rotational axis of theimpeller, said impeller being in the form of a substantially circularplate, said vanes being disposed radially on each surface of the plate,the central portion of the plate including aperture forming meanstherein enabling flowable material to be impelled by the vanes on bothsides of the impeller, said inlet means being in the form of a tubularmember having an inlet pipe communicated therewith, said shaft beingdisposed in said tubular member, seal means interconnecting the shaftand tubular member outwardly of the inlet pipe for sealing the shaft,and bearing means on said casing axially outwardly of the tubular memberfor supporting said shaft in relation to the casing, and means enablingcirculation of cooling fluid in relation to the bearing means forpreventing excessive temperatures occurring in the bearing means.
 6. Thestructure as defined in claim 5 wherein said means enabling circulationof cooling fluid including a pipe extending from the periphery of thechamber in the casing for inlet of cooling fluid, a pipe communicatingwith the tubular member to return the cooling fluid to the inlet meanson the pump, and a jacket encircling the bearing means for enablingcirculation of cooling fluid.
 7. The structure as defined in claim 6wherein said seal means includes a tubular member disposedconcentrically within the tubular member defining the iNlet means andreceiving a plurality of seal rings therein in sealing engagement withthe shaft, lubrication means for said seal rings, said lubrication meansincluding a piston and cylinder to force lubrication means into the sealrings, and conduit means interconnecting the lubrication cylinder andpiston and the pipe extending from the periphery of the chamber in thecasing for inlet of cooling fluid to the jacket thereby providingpressure lubrication of the seal rings.
 8. A rotary pump comprising acasing having an interior hollow chamber, a rotary impeller disposed insaid chamber, a shaft connected with said impeller and extendingexteriorly of the casing for rotary driving the impeller, inlet means insaid casing for admitting flowable material to be pumped to the centralportion of the impeller, said impeller including vanes thereon forimpelling the material as the impeller rotates, outlet meansincorporated into the casing and communicating with the portion of thecasing receiving the periphery of the impeller for receiving thematerial impelled by the impeller, sad outlet means including inwardlyextending passage defining means communicating with an outlet pipegenerally coincident to the rotational axis of the impeller, saidimpeller being in the form of a substantially circular plate, said vanesbeing disposed radially on each surface of the plate, the centralportion of the plate including aperture forming means therein enablingflowable material to be impelled by the vanes on both sides of theimpeller, said impeller including a centrally disposed annular ring oneach side thereof in encircling relation to the aperture means, one ofthe rings being received closely within the inlet means, said casingincluding a recess receiving the other annular ring
 9. A rotary pumpcomprising a casing having an interior hollow chamber, a rotary impellerdisposed in said chamber, a shaft connected with said impeller andextending exteriorly of the casing for rotatably driving the impeller,inlet means in said casing for admitting flowable material to be pumpedto the central portion of the impeller, said impeller including vanesthereon for impelling the material as the impeller rotates, outlet meansincorporated into the casing and communicating with the portion of thecasing receiving the periphery of the impeller for receiving thematerial impelled by the impeller, said outlet means including inwardlyextending passage defining means communicating with an outlet pipegenerally coincident to the rotational axis of the impeller, said outletmeans including a substantially circular plate defining the rear surfaceof the chamber, said radially extending passage defining means beingrigid with said plate, tapering inlet channels communicating the outerperiphery of the chamber with the radial passage defining means.
 10. Thestructure as defined in claim 9 wherein said casing is provided with adeflector ring at the outer periphery of the impeller, said deflectorring including a plurality of radial notches therein with each of thenotches including an inclined surface extending circumferentially in thedirection of rotation and inclined axially toward the channels fordeflecting the material being pumped into the channels and passagedefining means for discharge.
 11. The structure as defined in claim 10together with an insert adapter for converting the pump to a multiplestage pump, said casing including an inlet portion and a dischargeportion, said portions of the casing being separable at the outerperiphery of the chamber, said insert adapter including a duplication ofthe discharge portion and the inlet portion of the casing, a duplicationof the impeller and deflector ring and an extension for the drive shaftfor enabling a single or multiple number of insert adapters to beincorporated into the pump to enable any number of stages to beprovided.
 12. The structure defined in claim 11 wherein said extensionfor the drive shaft is threadly connected thereto and Includes aduplicate connection with the impeller.
 13. A rotary pump comprising acasing having a hollow interior chamber with an inlet at one sidethereof, a rotary impeller disposed within said chamber and separatingthe chamber into two compartments with the inlet communicating with onecompartment, said impeller including a plate of generally circularconfiguration with the periphery of the pate being disposed closelyadjacent the internal periphery of the chamber, said plate includingcentrally disposed aperture means communicating the compartments of thechamber with each other and enabling inlet of flowable material from theinlet to both compartments for hydraulically balancing the impeller,said impeller plate including projecting vanes on both surfaces thereoffor impelling flowable material thereof during rotation, and dischargemeans communicated with the casing for discharge of flowable materialbeing pumped.